Installing Windows on a USB

installing-windows-on-a-usb.txt

Requirements
============

* USB device (actually, any storage device works) with an appropriate size for the OS
* A target computer capable of booting from the device

Before you start
================

* Don't run commands blindly
* Customize commands as needed
* ? is a placeholder for something

Setup
=====

* Insert the installation media into the computer and boot from it
* When the installer finishes loading, hit Shift+F10 to get a command prompt
* Note the drive letter of the installation media - probably X or D or E

Prepare the USB with DISKPART
=============================

?:\> DISKPART
DISKPART> LIST DISK

* Note the disk number of the USB

DISKPART> SELECT DISK ?
DISKPART> CLEAN
DISKPART> CREATE PARTITION PRIMARY
DISKPART> FORMAT QUICK FS=NTFS
DISKPART> ACTIVE

* Unassign C: from any existing drives

DISKPART> LIST VOLUME

* If there is any volume mounted to C: then remove it
* If somehow C: is the installation media, and it really shouldn't be, then don't REMOVE but ASSIGN a different letter

DISKPART> SELECT VOLUME ?
DISKPART> REMOVE

* Go back to the USB and assign it C:

DISKPART> SELECT DISK ?
DISKPART> ASSIGN LETTER=C
DISKPART> EXIT

?:\> C:
C:\> DIR /A

* Make sure the drive is empty and that the free space reported sounds right

Install Windows
===============

* ?:\sources\install.wim should be the path to the installation data from the media
* install.wim supports multiple OS types, with indexes starting from 1 - as listed in the installer UI when it asks what to install
  - Windows Server example: 1=Standard Core, 2=Standard UI, 3=Datacenter Core, 4=Datacenter UI

C:\> DISM /Apply-Image /ImageFile:?:\sources\install.wim /Index:? /ApplyDir:C:\

* Install the bootloader

C:\> BOOTSECT /nt60 C: /mbr
C:\> BCDBOOT C:\Windows /s C: /f ALL

* Hyper-V Server, or Windows with the Hyper-V role pre-installed, may need the hypervisor enabled at boot
* If you don't do this and it's necessary, the system will tell you that Hyper-V isn't working

C:\> BCDEDIT /store C:\BOOT\BCD /set {default} hypervisorlaunchtype Auto

Disable Paging
==============

* Paging can mean a lot of writing and that will hurt the lifetime of a USB device - but make sure you have plenty of memory
* The ExistingPageFiles setting probably won't exist for new installations, in which case the REG DELETE will error

C:\> REG LOAD HKLM\foo C:\Windows\system32\config\SYSTEM
C:\> REG ADD "HKLM\foo\ControlSet001\Control\Session Manager\Memory Management" /v PagingFiles /t REG_MULTI_SZ /d "" /f
C:\> REG DELETE "HKLM\foo\ControlSet001\Control\Session Manager\Memory Management" /v ExistingPageFiles /f
C:\> REG UNLOAD HKLM\foo

Reboot
======

Sources
=======
* https://web.archive.org/web/20190831154752/https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/microsoft-hyper-v-server-2008-R2/ee731893(v=ws.10)
* https://web.archive.org/web/20190912065716/https://www.danielstechblog.info/how-to-deploy-windows-server-2016-tp3-onto-an-sd-card/
* Google